High levels of arsenic found last month at the sprawling Chapman Field Park in Coral Gables do not extend beyond the baseball fields where the toxic metal was originally found, and probably came from dirt trucked in to construct the fields, Miami-Dade County officials said this week after sampling more soil.

“It was very important to determine if there was contamination in sites outside the park, which there was not,” said Wilbur Mayorga, director of the county’s Division of Environmental Resources Management.

The initial discovery showed arsenic more than 20 times normal levels at the 560-acre park at 13601 Deering Bay Dr. And while it is not uncommon to find traces of arsenic in places like Miami, where the soil is rich in marine sediments and fossils, the alarmingly high levels puzzled officials.

The most recent soil sampling also confirmed that there was no evidence of solid waste in Chapman Field, unlike the contamination found in other parks where officials believe incinerator ash was either dumped or used to fill former quarries.

Chapman Field Park, named for Victor Chapman, the first American pilot to die in battle, was used as an airfield during the two world wars, leading some park users to speculate that its past as a military base could explain the presence of arsenic. However, officials do not believe the contamination is related to the park’s military history.

“The material used to develop the baseball fields seems to be the potential source of the arsenic,” said Mayorga. At this point, DERM cannot say where the soil came from, or when it was implemented in the fields’ construction.

According to Mayorga, DERM is hiring an independent consultant to complete the evaluation of Chapman Field Park and recommend a clean-up plan. Until the evaluation is complete, the county cannot say when the baseball fields will be safe to reopen.

The contamination raised concern among the park’s users. Manuel Ferrero, director of International Slow Pitch Softball, said some of his players have been using the fields, which he described as some of the best in the county, for 30 years.

“I think the results are even more alarming now that we know that they are confined to the baseball fields,” Ferrero said. “Our first priority is the safety of our players.”

But county health officials said the health risk is very low.

“You would have to have eaten the soil for many years before you would experience any potential health impact,” said Samir Elmir, division director for the Miami-Dade Department of Public Health. He said health risks associated with inhalation are even lower than for consumption. If anyone has concerns, he recommends that they consult with their physicians to determine whether testing is necessary.

Despite the relatively low health risks, Ferrero and his organization are discussing canceling the league’s summer tournaments until his players are tested.

“I think that the county should at least should get everyone tested, especially the players, just to be safe,” he said.

The contamination was discovered during sampling of all 263 county parks, a survey sparked in 2011 after federal investigators discovered chemical contamination at Olinda Park, built on an old dump in West Miami-Dade. The county has tested almost 200 parks and has found contamination only at Brothers to the Rescue Park, which sits next to the site of an old municipal incinerator in Coral Gables.

“Sadly, we are all still dealing with the practices that existed before environmental laws existed,” said Mayorga.